An anonymous reader points out a story in The Register by Opera Software CTO Hakon Lie which tells the story of how Microsoft's interoperability promise for IE8 seems to have been broken in less than six months
"In March, Microsoft announced that their upcoming Internet Explorer 8 would: use its most standards compliant mode, IE8 Standards, as the default. Note the last word: default. Microsoft argued that, in light of their newly published interoperability principles, it was the right thing to do. This declaration heralded an about-face and was widely praised by the web standards community; people were stunned and delighted by Microsoft's promise. This week, the promise was broken."